The Case of the Missing Memory - S1.E55

Sundown, while suffering from amnesia after being knocked out by a fallen lamp post, unwittingly teaches Big Boss' Crooks all the tricks and traits of what it's like to be a cowboy, not knowing that this is part of Big Boss' plot to use Sundown as a pawn to commit an armored truck robbery. Sundown later regains his memory and helps the C.O.P.S. team put a stop to the heist and nab the rustlers along the way.